Electrical connector for a light source

ABSTRACT

The electrical connector is used for connection to a light source having a contact element (20) for electrical connection with a positive terminal of a voltage source and a base plate (18) and/or base section (22) for a ground connection. The electrical connector includes a plug part (30) having a contacting receptacle (32) formed to fit together with the contact element (20) of the light source, an electrically insulating sheath (36, 38, 40) and a ground contact element (50) arranged on the sheath (38). The electrically insulating sheath is provided with an opening (44) for insertion of the contact element (20) so that the contacting receptacle (32) is contacted by the contact element (20). The ground contact element (50) has a sleeve-like section (52) arranged on the sheath (38), and advantageously two contact arms (54) extending from the sleeve-like section (52) toward the light source (14) and bent toward the contact element (20) to bear under tension against the base plate (18) or base section (22) when the contact element (20) is inserted into the plug part (30).

BACKGROUND OF THE INVENTION

The present invention relates to an electrical connector for a lightsource, especially for a light source in a headlight of a vehicle.

A known electrical connector of this type is disclosed by DE 38 31371A1. There, the light source is an incandescent lamp of the type H1,fitted into a reflector of a headlamp for vehicles. This light sourcehas a contact pin, which serves for the electrical connection of thelight source to the positive terminal of a voltage source. In addition,the light source has a base, via which the ground connection of thelight source takes place. For connecting the light source to thepositive terminal of the voltage source, a plug part is pushed on to itscontact pin. Acting on the base of the light source is a metallicretaining clip, by which the light source is retained on the reflectorand this retaining clip has a plug contact, on to which there can bepushed a further plug part, which establishes a ground connection of thelight source. Consequently, for the electrical contacting of the lightsource, here two separate plug parts have to be fitted, which means thatconsiderable work is involved.

ADVANTAGES OF THE INVENTION

It is an object of the present invention to provide an electricalconnector for a light source, especially for a light source used in theheadlight or other lighting device of a vehicle, which avoids theabove-described disadvantages.

This object and others which will become more apparent hereinafter areattained in an electrical connector for a light source, the light sourcehaving a contact element for connection with a positive terminal of avoltage source and a base for a ground connection, the electricalconnector comprising a plug part having a contacting receptacle formedto fit together with the contact element, advantageously a contact pin,of the light source.

According to the invention, the plug part has an electrically insulatingsheath provided with an opening for insertion of the contact element sothat the contacting receptacle is contacted by the contact element, anda ground contact element arranged on the sheath. This ground contactelement has a sleeve-like section arranged on the sheath, and at leastone resilient contact arm extending from the sleeve-like section towardthe light source and bearing under tension against the base transverselyto the fitting direction of the plug part on the contact element whenthe contact element is plugged into the plug part.

The electrical connector for a light source according to the invention,has in comparison the advantage that only one plug part by which theconnection of the light source to the positive terminal of the voltagesource and the ground connection are established at the same time needsto be connected to the light source.

The electrical connector according to the invention is particularlycompact because the ground contact element only slightly increases theoverall size of the plug part.

Several embodiments with advantageous additional features are possible.The end region of the at least one contact arm coming to bear againstthe base of the light source preferably is U-shaped and curved so as tohave a vertex pointing toward the base. Advantageously the sleeve-likesection of the ground contact element has two of the contact armsdiametrically opposed to each other and with vertices pointing towardeach other. Because of these features short circuits created by thecontact element or pin of the light source on insertion of it into theplug part are avoided.

BRIEF DESCRIPTION OF THE DRAWING

The objects, features and advantages of the invention will now beillustrated in more detail with the aid of the following description ofthe exemplary embodiment, with reference to the accompanying figures inwhich:

FIG. 1 is a partially cross-sectional, partially side, view of a lightsource and an electrical connector according to the invention;

FIG. 2 is a detailed cross-sectional view through the electricalconnector according to the invention shown in FIG. 1 at the start ofconnection of the light source to the electrical connector;

FIG. 3 is a transverse cross-sectional view taken through the electricalconnector of FIGS. 1 and 2 along the section line III--III in FIG. 2showing the contact element only partially inserted in the electricalconnector; and

FIG. 4 is another detailed cross-sectional view through the electricalconnector similar to FIG. 2 with the contact element of the light sourceinserted fully into the electrical connector and showing the contactarms contacting the light source base.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

In FIG. 1 a lighting means for a vehicle which is a headlight, but mayalso be a luminaire or the like, is shown. The headlight has a reflector10, with an opening 12, into which a light source 14 is fitted. In thecase of the exemplary embodiment, the light source 14 is an incandescentlamp, in particular of the H1 type, and has a coiled filament as theluminous element. The light source 14 is retained on the reflector 10,for example by means of a spring clip 16, which acts on the base plate18 of the light source 14. The light source 14 has a contact pin 20acting as the contact element on the face end of its base facing awayfrom the reflector 10 which serves for the connection to the positiveterminal of a voltage source. The contact pin 20 is provided with a bore21 or a depression. The ground connection of the light source 14 takesplace via its metallic base plate 18 or a metallic, approximatelycuboidal or cylindrical base section 22 adjoining this plate. Betweenthe metallic base section 22 and the contact pin 20 there is a section24 of electrically insulating material, the diameter of which issomewhat smaller than that of the base section 22.

The electrical connector of the light source 14 comprises a plug part30, which can be pushed on to the contact pin 20 of the light source 14in the direction of the arrow 31. The plug part 30 is shown in detail inFIG. 2. The plug part 30 has a contacting receptacle 32, in thisembodiment a contacting sleeve, which is connected via an electricalline 34 to the positive terminal of a voltage source, in the case of theexemplary embodiment of the on-board battery of the vehicle, via a lightswitch. The receptacle 32 has a resilient projection 33, which protrudesinward from it and inter-acts with the bore 21 in the contact pin 20.The plug part 30 has an electrically insulating sheath 36, which has asection 38 surrounding the receptacle 32 and has a section 40surrounding the connection piece of the electrical line 34. The line 34may extend out of the plug part 30 approximately coaxially to thefitting direction 31 of the plug part 30 or transversely thereto. Thesection 38 of the sheath 36 surrounding the receptacle 32 has arectangular cross-section transverse to the fitting direction 31 of theplug part 30 and has on its front face end, facing toward the lightsource 14, a wall 42, in which there is an opening 44 for the insertionof the contact pin 20 of the light source 14. The cross section of theopening 44 is in this case adapted to that of the contact pin 20 suchthat the contact pin 20 passes through the opening 44 with littleclearance transversely to the fitting direction 31 of the plug part 30.With a simple configuration of the plug part 30, the receptacle 32 isfixed within the sheath 38 in a way not shown. The plug part 30 may,however, also be designed to achieve a so-called positive-lock function.In this case, the end of the receptacle 32 facing toward the lightsource 14 is arranged at a distance from the wall 42 of the sheath 38.Protruding from the inner side of the sheath 38 toward the receptacle 32is a lug 45, which engages in a recess 46 in the receptacle 32. Alsoprotruding from the sheath 38 toward the receptacle 32 is a projection47, which is provided with a ramp 48, facing counter to the fittingdirection 31. Protruding from the receptacle 32 transversely to thefitting direction 31 is an arm 49, which can be swiveled elastically andcomes to bear against the ramp 48.

During connection of the plug part 30, its sheath 36 is acted upon andthe plug part 30 is pushed in the direction of the arrow 31 onto thelight source, the receptacle 32 being supported on the lug 45 by the rimof its recess 46 neighbouring the light source 14, so that thereceptacle 32 cannot move axially with respect to the sheath 36 and thecontact pin 20 enters into the latter. In the end position of the plugpart 30, which is determined by the bearing of the face end of theinsulating section 24 of the base of the light source 14 against thewall 42 of the sheath 36, the projection 33 of the receptacle 32 catchesin the bore 21 in the contact pin 20. In the removal of the plug part30, its sheath 36 is acted upon and the latter is drawn counter to thearrow direction 31 from the light source 14. In this case, the arm 49slides over the ramp 48 on the projection 47, the part of the receptacle32 with the projection 33 thereby being swiveled, so that the projection33 is lifted out of the bore 21 in the contact pin 20. When the wall 42comes to bear against the face end of the receptacle 32 after thedistance s, the plug part 30 can be taken off the light source 14 withlittle exertional force upon further movement counter to fittingdirection 31.

Arranged on the section 38 of the sheath 36 surrounding the receptacle32 is a metallic ground contact element 50, which is connected via aline 51 to ground. The ground contact element 50 comprises a sleeve-likesection 52, which is retained on the section 38, and two resilientcontact arms 54, protruding from said section toward the light source 14in fitting direction 31 of the plug part 30. The sleeve-like section 52is pushed on to the section 38 counter to the arrow direction 31 and,like the latter section, has a rectangular cross-section transverse tothe fitting direction 31. The sleeve-like section 52 has a slit 56, sothat it can be elastically expanded transversely to the fittingdirection 31. In addition, on two mutually opposite side walls of thesleeve-like section 52 there is in each case an opening 58. From twomutually opposite outer sides of the section 38 of the sheath 36 thereprotrudes outward in each case a projection 60, which is bevelled towardthe light source 14. Also protruding from the sleeve-like section 52,facing away from the light source 14, is a contact tab 62, to which theline 51 is connected. The ends of the sleeve-like section 52 facing awayfrom the light source 14 are bent over outward, in order to permit easypushing-on onto the section 38 of the sheath 36.

The contact arms 54 are bent toward each other in their regionprotruding beyond the section 38 of the sheath 36 and their ends arebent in a U-shaped manner, the vertices V of the U-shaped ends of thetwo contact arms 54 facing each other. The contact arms 54 are providedwith a bead 55 in their resilient region, in order to increase theirflexural rigidity. The distance D_(c) between the ends of the contactarms 54 with respect to each other is somewhat smaller than the diameterD_(b) of the cylindrical base section 22 of the light source 14.

For the fitting of the ground contact element 50, its sleeve-likesection 52 is pushed on to the section 38 of the sheath counter to arrowdirection 31. The width of the section 38 of the sheath 36 in the regionof the two sides facing the projections 60 is somewhat greater than thecross section-of the sleeve-like section 52, so that the latter isexpanded somewhat, which is made possible by its slit 56. In the endposition of the ground contact element 50, the projections 60 passthrough the opening 58 in the sleeve-like section 52, as a result ofwhich a catch-like fastening of the contact element 50 on the section 38is achieved.

In the fitting of the plug part 30 on to the light source 14, thecontact arms 54 of the ground contact element 50 are bent apart whenthey meet with their ends the insulating section 24 of the base of thelight source 14. In the end position of the plug part 30, the contactarms 54 bear with their ends radially against the cylindrical basesection 22 of the light source 14 under tension as shown in FIG. 4, sothat the connection on the positive side and the ground connection ofthe light source 14 are established at the same time by the plug part30.

The distance between the ends of the contact arms 54 and the end of thereceptacle 32 facing the light source 14 and the cross section of theopening 44 through which the contact pin 20 passes are in this casematched to each other such that the contact pin 20 cannot come to bearas the result of an oblique positioning simultaneously against the endsof the contact arms 54 and against the receptacle 32, which would resultin a short circuit. In this case, the distance between the end of thereceptacle 32 facing the light source 14 and the wall 42 must also betaken into consideration. An oblique positioning of the contact pin 20in a plane containing the two contact arms 54 is restricted by the factthat the contact pin passes through the opening 44 only with slightclearance. The smaller the distance of the ends of the contact arms 54from the wall 42 of the sheath 36, the more the contact pin 20 can beobliquely positioned without at the same time coming to bear against thereceptacle 32 and the ends of the contact arms 54. Conversely, theoblique positioning of the contact pin 20 must be restricted all themore closely the greater the distance of the ends of the contact arms 54from the wall 42 of the sheath.

As a departure from the configuration described above, the contact arms54 of the ground contact element 50 may also be designed such that theycan come to bear against the base plate 18 of the light source 14. Inaddition, there may also be provided only one contact arm 54 or morethan two contact arms 54. Finally, the light source 14 may also have adifferent contact element than the contact pin 20, for example areceptacle, the plug part 30 then having a plug-in element designed forinteracting with the contact element.

The electrical contacting of a light source described above is notrestricted to the application in the case of an H1 incandescent lamp butcan be applied generally in the case of light sources with which aconnection contact is provided only for the connection on the positiveside, and the ground connection takes place via the base of the lightsource.

We claim:
 1. An electrical connector for a light source, the lightsource (14) having a contact element (20) for connection with a positiveterminal of a voltage source the light source having a metallic baseplate (18) and a cylindrical base section (22) for a ground connection,said electrical connector comprising a plug part (30) having acontacting receptacle (32) formed to fit together with and to contactthe contact element (20) of the light source, an electrically insulatingsheath (36, 38, 40), said electrically insulating sheath being providedwith an opening (44) for insertion of the contact element (20) in saidsheath so that the contacting receptacle is contacted by the contactelement (20), and a ground contact element (50) arranged on the sheath(38),wherein said ground contact element (50) has a sleeve-like section(52) arranged around the sheath (38) and at least one resilient contactarm (54), said at least one resilient contact arm (54) extends from saidsleeve-like section (52) toward the light source (14), said at least oneresilient contact arm (54) bears against the base plate (18) or basesection (22) under tension and said at least one resilient contact arm(54) having an end portion bent toward the contact element (20) in adirection transverse to an engagement direction (31) of the plug part(30) so as to bear on the base plate (18) or base section (22) when thecontact element (20) is plugged into the plug part (30).
 2. Theelectrical connector as defined in claim 1, wherein the opening (44) isof a size such that the contact element (20) passes through said openingwith a clearance small enough so that, during an oblique insertion ofthe contact element (20) in the electrically insulating sheath(36,38,40), the contact element (20) does not contact both thereceptacle (32) and the at least one contact arm (54) at the same time.3. The electrical connector as defined in claim 1, wherein the endportion of the at least one contact arm (54) comes to bear against thecylindrical base section (22) of the light source (14) and has a vertex(V) pointing toward said base section (22).
 4. The electrical connectoras defined in claim 1, wherein the sleeve-like section (52) can bepushed onto the electrically insulating sheath (38) and is elasticallydeformable transversely to said engagement direction.
 5. The electricalconnector as defined in claim 1, further comprising catch means (58,60)for retaining the ground contact element (50) on the insulating sheath(38).
 6. The electrical connector as defined in claim 1, wherein the atleast one contact arm (54) has a resilient region and means forstiffening said resilient region.
 7. The electrical connector as definedin claim 6, wherein said means for stiffening comprises a bead in theresilient region of said at least one contact arm (54).
 8. Theelectrical connector as defined in claim 1, wherein the light source(14) is an incandescent lamp for a headlight of a vehicle.
 9. Theelectrical connector as defined in claim 1, wherein the contactingreceptacle (32) is positioned inside the electrically insulating sheath.